How to be "superuser"

How do I get “superuser” access in MySQL?

The phpMyAdmin guide tells me that to create the ‘controluser’ I need to be superuser.

If I am connected via SSH (command line console) do I “su” in the bash shell? If so what password is it looking for?

If I am in the MySQL command line, what is the syntax and password?

Can I get ‘superuser’ access from within phpMyAdmin? How? What password does it want?

Thank you.